This Over-the-Shoulder Personal Cooling Vest has been used by the U.S. military for more than 15 years. Simply freeze the reusable gel packs (Item Number G10121, sold separately) and insert into the personal cooling vest for up to 4 hours of cool comfort while you work in hot, humid conditions. Gel packs remain flexible when frozen, so you can move without restriction. Great for layering. Durable, flame-resistant, 100% cotton outer shell. Hook-and-loop side closure. Over-the-shoulder style holds six gel pack strips. Fits chest sizes 38"?57". USA made.